A photosensor substrate for a flat panel can be formed by arraying, on a substrate, switching elements and photoelectric transducers in a matrix form. Such a photosensor substrate is applicable to a contact image sensor, an X-ray imaging display device, and the like. For example, Patent Literature 1 describes forming a two dimensional photovoltaic device including a metal-insulator-semiconductor (MIS) sensor in combination with a thin film transistor (TFT).
Patent Literature 2 discloses a sensor substrate including a plurality of photodiodes (photoelectric transducers) provided on a substrate, and TFTs each functioning as a driver element. The sensor substrate includes a wavelength conversion layer that converts a wavelength of incident radial rays to fall within a sensitivity range of the photoelectric transducers. The wavelength conversion layer is made of a scintillator (fluorescent material) that converts X-rays to visible rays.
A flat panel X-ray imaging display device (flat panel detector (FPD)) of an indirect conversion type, which is configured to convert X-rays to visible rays by means of a scintillator and detect the converted rays, has been attracting attention with expected application in medical industries and the like.
A FPD can be of the indirect conversion type, or can be of a direct conversion type configured to convert X-rays directly to electric charges by means of an X-ray detecting element typically exemplified by Se. The FPD of the indirect conversion type achieves higher quantum efficiency and a higher signal to noise ratio (S/N ratio) than that of the direct conversion type. The FPD of the indirect conversion type thus enables fluoroscopy and photographing with a fewer exposed dose.